משנה על כלים 1:8

Within it was the Soreg, ten handbreadths high. There were thirteen breaches in it, which had been originally made by the kings of Greece, and when they repaired them they enacted that thirteen prostrations should be made facing them. Within this was the Hel, which was ten cubits [broad]. There were twelve steps there. The height of each step was half a cubit and its tread was half a cubit. All the steps in the Temple were half a cubit high with a tread of half a cubit, except those of the Porch. All the doorways in the Temple were twenty cubits high and ten cubits broad except those of the Porch. All the doorways there had doors in them except those of the Porch. All the gates there had lintels except that of Taddi which had two stones inclined to one another. All the original gates were changed for gates of gold except the gates of Nicanor, because a miracle happened with them. Some say: because their copper gleamed like gold.